PHILADELPHIA (CBS) — Motorists stuck on the Pennsylvania Turnpike (see related story) should be careful how long they keep those vehicles running.

That’s the advice of Jim Lardear of AAA, the automobile advocacy group, who provided some commonsense tips for survival in the backup.

He says motorists should run their engines sparingly — assuming the car is not damaged — because there’s no telling how long that jam-up is going to last.

He says turn off your engine but, if you get cold, turn the vehicle on for three to four minutes — just enough to warm up or to make a phone call if your cell phone battery is dead.

“The other thing you have to watch for is to avoid asphyxiation from carbon monoxide poisoning,” he notes, “so don’t let the car run for a long time with the car windows closed.”

He says it all depends on how the exhaust and ventilation systems are working.

Lardear says it also helps that people are getting out of their cars and talking to each other, and sharing water and other supplies. He says being patient and kind to strangers will help everyone get through this safely.